1. Field of the Invention
The invention relates generally to monitoring aspects of water chemistry and more specifically to methods and reusable devices for detecting and continuously monitoring pH of aquatic environments.
2. Background Information
The balance of various chemical components or parameters in an aquatic environment is generally referred to as “water chemistry”. Water chemistry is highly determinative of the health and safety of an aquatic environment and the suitability of water for various uses. In many aquatic environments such as fisheries, lakes, drinking water, including recreational waters such as pools, spas, and hot tubs, maintenance of conditions suitable for use, potability, healthy bathing, etc., as well as an aesthetically pleasing environment, is highly dependent on a proper balance of water chemistry parameters. Maintaining a proper water chemistry balance requires constant monitoring and is necessary in preventing the unwanted effects of altered water chemistry, such as skin and eye irritation of bathers, cloudy water, staining and corrosion of pool equipment, and formation of unsightly mineral deposits. Additionally, monitoring and maintaining proper water chemistry in drinking water or environments containing aquatic life (e.g., fish), such as fisheries or aquariums, is vital to ensuring conditions that ensure a healthy water supply, as well as ensure the health and survival of the aquatic life present. For example, altered levels of ammonia or nitrogen, or incorrect pH levels can result in discolored water, algae blooms, outbreak of disease, and fish loss. As such, accurately determining various aspects of water chemistry is of critical importance for determining the suitability of water for various applications, as well as maintaining the health and safety of a water sample.
Water pH is one of the most important parameters of water chemistry. The pH scale is a measure of the acidity or amount of free hydrogen ions in the water. The pH scale extends from 0 to 14, with a pH value of 7.0 corresponding to a neutral pH. As the pH moves lower than 7.0, the water becomes increasingly acidic, and as the pH moves higher than 7.0, the water becomes less acidic and more basic. Because pH is measured with a logarithmic scale, very small changes in the value indicate large changes in hydrogen ion concentration. For example, a change of one pH unit corresponds to a ten fold difference in the number of free hydrogen ions. The pH value of aquatic environments such as aquariums, pools, and spas is vital not only because it is itself an important parameter, but also because other water chemistry parameters (e.g., ammonia, total alkalinity, chlorine, and phosphates) are dependent on the pH value. Because of the importance of this parameter, the pH of aquariums, pools, and hot-tubs must be monitored frequently to adjust accordingly to small changes in the pH values.
Several methods are currently used to test the pH value of aquatic environments. Perhaps the most common method is a method utilizing solutions containing indicator dyes, which change color corresponding to the pH of the water sample. Such methods include removing a small sample of water from the aquatic environment and adding a dye solution calibrated to test the pH. The combination of the dye solution and the water sample is allowed to develop a color, and the color of the water-dye mix is compared to reference colors corresponding to pH values. The solutions are then discarded following comparison of the water-dye mix to reference colors and determining the pH of the sample. This method is inexpensive, making it popular for residential applications, but is time consuming and user-intensive. The user must first remember to check the pH, and then perform several physical tasks before the results of the test are known. Additionally, the user must handle chemicals that are harmful and/or corrosive, with the added potential to stain various fabrics due to the dye nature of the testing compounds.
Another method commonly used to test the pH of a water sample involves use of indicator dyes deposited on test strips. According to these methods, a test strip is dipped into the water sample, allowing a color to develop. The color of the developed test strip is then compared to reference colors corresponding to known pH values, allowing identification of the pH of the water sample. This method is gaining popularity due to the convenience factor, but is limited due to an increased expense relative to the solution based methods. The test strips are not reusable or reversible, and the user must discard the test strip after using the product, thereby adding to the cost of this method. In addition, test strips rapidly degrade when left in aqueous solution and are not suitable for continuous monitoring of water chemistry.
Unfortunately, a product has not yet been described that allows continuous monitoring of an aquatic environment, is inexpensive and accurate, and is suitable for continuous pH monitoring and reuse in multiple applications. Thus, a need exists for reusable devices and methods for continuously monitoring the pH of an aquatic environment that are inexpensive and accurate, and that remove the requirement of the user to physically perform multiple mixing and measuring steps.